Sometimes when force-quitting apps from your App Switcher, you end up closing an app that’s playing media in the background by accident. This forces you to re-open the app and re-play the song you were just listening to from the beginning... all over again.
If you do this quite often, then you probably have App Switcher OCD and are clearing your App Switcher more often than you need to, but that’s beside the point; a new free jailbreak tweak called NoClose by Skylerk99 can help prevent you from accidentally force-quitting apps that are playing media in the background by prompting you beforehand.